Method of regulating growth of plants



United States Patent 9 3,326,662 METHOD OF REGULATING GROWTH OF PLANTS Tomoyoshi Toyosato, Kyoto, Michihiko Ochiai, Suita, Hiroshi Hagimoto and Hiroshi Tarmura, Kyoto, and Toshiya Kamikado, Suita, Japan, assignors to Takeda Chemical Industries, Ltd., Higashi-ku, Osaka, Japan No Drawing. Original application Aug. 9, 1963, Ser. No. 301,201. Divided and this application Apr. 29, 1966, Ser- No. 560,920

Claims priority, application Japan, Aug. 10, 1962,

37/3 1,645 3 Claims. (Cl. 712.5)

This application is a division of application Ser. No. 301,201, filed Aug. 9, 1963.

The present invention relates to novel pyrazole derivatives and to their use for agricultural purposes. More particularly, the said pyrazole derivatives are those of the wherein R stands for H, lower alkyl, lower aralkyl or aryl, R stands for H, halogen, nitro, nitroso, cyano or lower alkoxycarbonyl, R stands for H, OH, NH lower alkyl, lower aralkyl, aryl or lower alkoxy, and R and R may form a benzene ring or a tetrahydrobenzene ring together with the carbon atoms in 4- and 5-positions of pyrazole ring, X stands for halogen, H, N0 lower alkyl, acyl, hydroxyalkyl, (lower)alkoxy(lower) alkyl or lower alkoxy, A stands for lower alkylene, and It stands for an integer from 1 to 5, inclusive.

The pyrazole derivatives of the above-mentioned Formula I have the effect to regulate growth of plants and, therefore, by a suitable choice of concentration of the pyrazole derivatives applied to plants and of the application method, the compounds regulate various growth phenomena of various plants, that is, leaf-expansion, shoot-elongation, root-imitation, fruit-development, fruit-ripening, flower-production and dormancy or, in the case of certain weeds, have a withering action.

There have been reported many kinds of plant growth I regulators, but only a few of them are actually utilized for agricultural purposes, because most of them cannot be used without risk of harm to desired cultural plants, or the agents are effective only to the non-intact plant, for example, to stem section, leaf disk or callus tissue, or a large amount of the agents is required, or the agents cannot be applied to plants before rain or in rain.

Although many attempts have been made to overcome the aforesaid shortcomings and other disadvantages, none, as far as the present inventors are aware, has been entirely successful when applied to practical use.

The present invention provides a series of new pyrazole derivatives of the above-mentioned Formula I, having a remarkable plant growth regulating activity upon application of a small quantity of compound to plants, with no discernible change in activity even in the case of rain just after an application to plants.

It is an object of the present invention to provide plant Patented June 20, 1 967 growth regulators which are free from the above-mentioned Shortcomings or disadvantages. Another object is to provide new pyrazole derivatives.

The present invention also contemplates providing methods for preparation of the said pyrazole derivatives. Among the further objects of the present invention is the provision of plant growth regulators which contain the pyrazole derivatives (I), and their use in regulating plant growth.

Other objects and advantages will become apparent from the following description taken in conjunction with the examples. 4

The pyrazole derivatives (I) of this invention can be synthesized through the reactions shown in the following reaction formulae:

In theabove-mentioned formulae, Y stands for a halogen, advantageously Cl, R stands for H or lower alkyl, B stands for an acyl, a cyano, or an alkoxycarbonyl group, and R R R X, n and A have the same significance as those in the Formula I, respectively.

The alkyl group represented by R R R or X in the foregoing formulae, is lower alkyl and may, for example, be methyl, ethyl, propyl, isopropyl, butyl or the like. As the halogen represented by R X or Y there may be chlotime or bromine. The alkyl group as the constituent of the alkoxy-carbonyl group represented by R or B, the alkyl group as the constituent of the alkoxy group represented by R or X, and the alkyl group as the constituent of hydroxyalkyl or alkoxy-alkyl represented by X in the formulae are likewise lower alkyl (cf. first sentence of the present paragraph).

When the compounds have two or more alkyl groups respectively represented by R R or R they may be the same as or different from each other. In case the number n is greater than 1, each X may be the same as or different from every other X.

Among the acyl groups represented by X or B in the above formulae, there may, for example, be included the forr'nyl, acetyl and benzoyl groups, and among the aralkyl groups represented by R or R there may, for example, be included benzyl and phenethyl groups.

The aryl group represented by R or R may, for example, be phenyl or substituted phenyl. The alkylene group represented by A may be a straight or branched chain, for example, it may be methylene, ethylene, trimethylene, tetramethylene, pentamethylene, ethylidene, l-methylethylene, Z-methylethylene, l-methylpropylene, or 2-ethylethylene. Furthermore, R and R may form a benzene ring or a tetrahydrobenzene ring together with the carbon atoms in 4- and 5-positions of the pyrazole ring.

As previously described, the pyrazole derivatives of the present invention may be provided by the reactions as shown in the above-mentioned reaction Formulae i or ii.

The reaction i may be carried out in the presence or absence of a suitable solvent. As solvent, there may be used such organic bases as pyridine, triethylamine, d1- methylaniline or the usual organic solvents such as acetone, methylethylketone, dimethylformamide, etc. The reaction is generally effected at room temperature (15 to 30 C.), and it may be controlled by heating or cooling, if necessar The reaction ii may be carried out in a suitable solvent. The solvent may, for example, be water, methanol, ethanol, acetic acid, benzene, etc., or a mixture consisting of two or more of these solvents. The reaction may be promoted by the addition of a small amount of acid to the reaction system. The reaction may be effected at room temperature, and may also be controlled by heating or cooling, if necessary.

The following list sets forth a wide variety of pyrazole derivatives prepared by the method of the present invention, which are useful as plant growth regulators according to the present invention:

( 1) 1- (4-chlorophenoxyacetyl) -3-methyl-4-nitro-5- phenylpyrazole (2) 1- 2,3,6-trichlorophenoxyacetyl -3 ,5 -dirnethyl pyrazole (3) 1- 2,3, 6-trichlorophenoxyacetyl -3 ,5 -dimethyl-4- chloropyrazole (4) 1- 2,3 ,6-trichlorophenoxyacetyl) -3,5-dimethyl-4- nitropyrazole (5) 1- 2,3 ,6-trichlorophenoxyacetyl) -3-methyl-5-phenylpyrazole (6) 1- 2,4-dinitrophenoxyacetyl -3,5-dimethyl-4-bromopyrazole (7) 1- 2,4-dinitrophenoxyacetyl -3,5-dimethyl-4-chloropyrazole (8) 1- 3-methoxyphenoxyacetyl -3,5-dimethylpyrazole (9) 1- (2-chlorophenoxyacetyl -3 -methyl-4-nitropyrazole 10) 1- (4-chlorophenoxypropionyl) -3,5-dibenzylpyrazole 11 l-(2,3,5,6-tetrachlorophenoxypropionyl) -3,5-di

(p-tolyl) -pyrazole (12) 1- 2,3 ,4,5, 6-p entachlorophenoxybutyl -3-ethylpyrazole (13) 1- (2-ethylphenoxyacetyl)-3,5-di(p-nitrophenyl) -4- bromopyrazole (14) 1- 2-ethoxyphenoxyacetyl -3,5-dibenzylpyrazole 15) 1- 2,4-dichlorophenoxyacetyl -4-cyano-5-aminopyrazole 16) 1- 2,4-dichlorophenoxyacetyl -4-ethoxycarbony1- 5 -methylpyrazole 17) 1- 2,4-dichlorophen-oxyacctyl) -4-ethoxycarbonyl- S-hydroxypyrazole 18) 1- 2-methyl-4-chlorophenoxyacetyl -4-ethoxycarbonyl-S-aminopyrazole (l9) 1- 2-methyl-4-chlorophenoxyacetyl -4-ethoxycarbonyl-S-methylpyrazole (20) 1- 2, 3 6-trichlorophenoxyacetyl) -3,5-dimethy1- pyrazole (21) 1- 2,3 ,4,5-tetrachlorophenoxyacetyl -3 ,5 -dimethylpyrazole (22) 1- 2-formyl-4-chlorophenoxyacetyl -3, S-dimethylpyrazole (23) 1- 2-formyl-4-chlorophenoxyacetyl) -3,5-dimethyl- 4-chloropyrazole (24) 1- oc- 2-formy1-4-chlorophenoxy propionyl] -3,5-

dimethyl-4-nitropyrazole (25) 1- [3- 2-hydroxymethyl-4-chlorophenoxy propionyl] -3,5-dimethyl- 4-nitropyrazole (26) l- 2-formyl-4-chlorophenoxyacetyl) -3-methyl-5- phenylpyrazole (27) 1- 2-formyl-4-chlorophenoxyacetyl -3 ,5 -dimethyl- 4-bromopyrazole (28) 1- 2-methoxymethyl-4-chlorophenoxy -3 -methyl- S-ethylpyrazole (29) 1-[a-(2-formyl-4-chlorophenoxy) propionyl] -3,5-

dibenzylpyrazole (30) 1- 2-hydroxymethyl-4-chlorophenoxyacetyl) -3,5-

dimethyl-4-chloropyrazole (31 1-(2-formyl-4-chlorophenoxyethyloxyacetyl)-3,5-

dimethylpyrazole (32) 1-(4-chlorophenoxyacetyl) -3methyl-4-nitro-5- phenylpyrazole (3 3) 1- 2,3 ,6-trichlorophenoxyacetyl -3 ,5 -dimethyl-4- bromopyrazole (3 4) 1- (2,3 6-trichlorophenoxyacetyl -3,5-diethyl-4- chloropyrazole (35) 1-(2,3,6-trichlorophenoxyacetyl) -3,5-dimethyl-4- nitropyrazole (36) 1-(2,3,6-trichlorophenoxyacetyl) -3-ethyl-5-phenylpyrazole (37) 1- (2,4-dinitrophenoxyacetyl)-3,5-diethyl-4-bromopyrazole (38.) l-(3-methoxyphenoxyacetyl) -3,5-dimethyl-4- chloropyrazole (39) 1-(2-chlorophenoxyacetyl) -3,5-dirnethylpyrazole (40) 1-(4-chlorophenoxypropionyl) -3-methyl-4-nitro-5- phenylpyrazole (41) 1- 2, 3,5, 6-tetrachlorophenoxypropionyl -3,5-di

(p-tolyl) -4-bromopyrazole (42) 1-(2,3,4,5,6-pentachlorophenoxybutyryl)-3-ethyl- 4-nitropyrazole (43) 1- 2-ethylphenoxyacetyl -3 ,5 -di( p-nitrophenyl) -4- chloropyrazole (44) 1-(2-ethoxyphenoxyacetyl)-3,5-dimethylpyrazole (45) 1- 2,4,5 -trichloro phenoxyacetyl) -4-cyan o-5 -aminopyrazole (46) 1- (4-chlorophenoxyacetyl) -4-cyano-5-aminopyrazole In practice, and to realize the desired activity, the plant growth regulators of the present invention are advantageously applied to plants in the form of the compositions such as dust, emulsion, suspension or solution. In other words, the plant growth regulator compositions of the present invention comprise essentially at least one active compound (pyrazole derivative) represented by the above-mentioned Formula I together with a suitable carrier (e.g. extender and/or conditioning agent) of the type commonly employed for the carriers of a known growth control agent. It is not intended, in this respect, that the present invention be limited to any specific proportions of active ingredient(s) (I) and adjuvant.

The compositions may be readily prepared ab initio or may e.g. be in the form of concentrates comprising active ingredient (I) with only a minor amount of an adjuvant, e.g. a surface active agent. Such a concentrate is economical as regards transportation, storage and the like, and may easily be admixedprior to usewith addltional adjuvant to give the desired concentration of the active ingredient When it is applied. The adjuvant may be selected depending on plants to be treated, properties of active ingredient and other adjuvant to be used together, and conditions of use.

Thus, if both the active ingredient and adjuvant (s) are Water-soluble, the composition may be applied in the form of an aqueous spray. If, for example, a water insoluble adjuvant is employed--e.g. if the composition comprises a water-insoluble adjuvant-the composition may be applied as an aqueous dispersion. It is also possible e.g. merely to mix the active agent, in powder form, with a powdery adjuvant and to use the mixture (dust). Or, the powder mixture may be suspended in water or in an oil, such as gasoline, kerosene, etc, which, upon mixing with water, forms e.g. an oil-in-Water emulsion containing the active ingredient. When the compositions are used in dust form, the adjuvant (or diluent) may e.g. be talc, clay, diatomaceous earth, lime, calcium sulfate, kaolin and the like.

When the compositions are used in the form of liquid, the adjuvant (diluent) is e.g. water, an aqueous solvent,

a volatile or non-volatile organic solvent, e.g. an alcohol such as methanol, ethanol, etc., a ketone such as acetone, methylethylketone, etc., an ether such as dioxane, tetrahydrofuran, etc., an aromatic hydrocarbon such as benzene, toluene, xylene, etc., a halogenated hydrocarbon such as chloroform, carbon tetrachloride, etc., an ester such as ethyl acetate and oil, etc., the composition--as afore-indicated-taking the form of a solution, emulsion or suspension depending on the nature of the materials employed.

The new plant growth regulating compositions may further contain wetting agents, dispersing agents and emulsifiers such as suitable surface active agents e.g. polyoxyethyleneglycolethers, polyoxyethyleneglycolesters, polyoxyethylene derivatives of sorbitan monolaurate (monooleate, monostearate), polyoxyethylenealkylarylether, alkyl sulfonate, alkylaryl sulfonate, alkyl sulfosuccinate, etc. They may also contain adherent or sticking agents, and also other agricultural chemicals, e.g. pesticides, fungicides, manure or fertilizer growth controlling agents, plants, hormones etc., all these materials being considered adjuvants.

It is within the scope of the present invention to employ other adjuvants than those hereinbefore mentionede.g. solid or liquid diluents, emulsifiers, dispersants, surface active agents or otherwise-those already mentioned being merely illustrative.

The essence of the present invention does not reside in any specific adjuvant but in a composition consisting essentially of at least one compound of the Formula I and an appropriate inert agricultural adjuvant which does not prejudice the activity of the composition.

Generally speaking, an eifective amount for plant growth regulation is satisfied with the following quantitative relationships.

A dust or oil composition for direct application to plants may contain from 0.00001 percent to 10 percent or more of the active ingredient(s) by weight. When the composition is prepared for actual use in the form of sprays or more dilute dusts, the content of the active ingredient(s) may vary from about 0.01 percent to as high as 0.1 percent by weight, the balance of the composition being one of the diluents and/ or surface active agents (adjuvants) previously mentioned.

Content of the active ingredient in an aqueous dispersion may similarly vary from a very low percentage, e.g. 1 percent by Weight, where the dispersion is applied directly to plants, to a relatively high percentage, e.g. 90 percent by weight, where the dispersion is employed as a concentrate, the balance in each case being constituted by an adjuvant or adjuvants.

The plant growth regulators of the present invention promote leaf-expansion, shoot-elongation, root-initiation, fruit-set, fruit-development, fruit-ripening, flower-production or break dormancy of plant (bud or'seed), or induce parthenocarpy, or inhibit absciss-layer formation at a considerable low concentration and inhibit growth or kill weeds at a considerable high concentration.

Among these uses of the present plant growth regulators effects on the regulation of fruit-development, i.e. effects on inducing parthenocarpy, inhibition of abscisslayer formation, fruit-drop prevention, stimulation of fruit-development, stimulation of fruit-ripening, and effect on suppressing or withering weeds are very prominent.

Heretofore, p-chlorophenoxy acetic acid, ,B-naphthoxy acetic acid, 2,4-dichlorophenoxy acetic acid, 2,4,5-trichlorophenoxypropionic acid, a-naphthaleneactic acid or a mixture of two or three of these have been put to use for fruitdrop prevention or fruit-set stimulation, eX- pecting their hormonal effect. These known compounds, however, are not free from the shortcomings that a large amount of the agents must be applied, or that the agents may do auxonic (hormonal) injury to plants to which they are applied.

The plant growth regulators of the present invention, on the other hand, display a superior hormonal effect on plants in spite of the application of a lesser amount in comparison with the above-mentioned compounds or their mixtures.

In application of the plant growth regulator of the present invention to plants for the purpose of growth promotion of the plants, it can be applied or sprayed onto seeds, roots, sprouts, stems, leaves, flowers, flower clusters, fruits, etc., in a suitable concentration for the purposes.

In application of the plant growth regulator of the present invention to plants for the purpose of growth inhibition of the plants or weeds, it can be applied to soil in pre-emergence of the plants or in post-emergence in a suitable concentration for the purpose.

In the treatment of paddy field weeds, the plant growth regulator may directly be applied to the plants or in paddy field where the plants grow. The plant growth regulator of the present invention can cause contact and auxonic (hormonal) injury, growth inhibition or withering of weeds by direct or indirect contact therewith, and moreover, the plant growth regulator displays intergenus-selectivity among gramineous plants.

Examples of regulative effect upon plant growth by application of the pyrazole derivatives (I) are set forth as follows:

EXAMPLE A Growth promotion test Growth-promoting and inhibiting action of the present compounds were tested by the Avena straight growth method. Ten pieces of 5 millimeter length of subapical section of Avena coleoptiles were soaked in the solution for 24 hours at 25 C. in the dark and their lengths were measured under the travelling microscope.

In the table, the compounds are represented by the corresponding numbers shown below:

1-(2,4-dichl-orophenoxyacetyll-3,5-dimethylpyrazole I l-(4-chlorophenoxacetyl)-3,5-dimethylpyrazole II l-(2,3,6-trichlorophenoxyacetyl)-3,5-dimethyl-4- chloropyrazole IH l- (2,4-dichlorophenoxyacetyl) -3-methyl-5-phenylpyrazole IV 1- 2,4,5 -trichlorophenoxyacetyl) -3 ,5 -dimethylpyrazole V 1- [a- 2,4-dichlorophen0xyl) propionyl] -3,5-dimethylpyrazole VI l-(2,4-dichlorophenoxyacethyl)indazole VII 1- 2-hydroxymethyl-4-chlorophenoXy-acetyl) -3,5-

dimethylpyrazole VIII 1-(2,4,S-trichlorophenoxyacetyl) 4,5,6,7-hexahydroindazole IX 7 TABLE-MEAN VALUE OF TEN SECTIONS Section length (milliliter) Concentration (p.p.m. 0 0.1 1 I 10 Tested compound:

I 6. 83 7. 42 5. 86 5. 07 6. 74 7. as 5. 70 5. 02 6. s2 7. 40 5. s1 5. 08 6. 51 6.98 6. 01 5. 78 6. 04 6.27 6.13 5. 96 5. 94 6.08 6.23 6. 14 6.43 7. 10 5. 74 5. 19 6. 24 6.73 6.15 5. 75 6. 32 6. 79 6. 04 5. 55

1 p.p.m. means concentration in parts per million.

'7 EXAMPLE B Fruit-set and fruit-development test (1) Conditions.

8 EXAMPLE C Fruit-set promotion test (1) Conditions.- Tested plants: Egg plant (Solanum. melongena).

Tested plant: Tomato (Lvcopersicon esculentum Mill). T t l One plant er one pot, 2O pots are Test Scale; 20 P /2000 wagl'lers P P 1 Plot, Wagners p ot) per 1 plot, 2 repetitions.

one Plant p one P 2 repetitions- Method: The solutions of the following four compounds The term plot used in following examples means a are apphed to flowers and P eduncles Wlth brush definite treated area of experiment in which the prepa- Result-4B the following Fable, the Compounds ration of this invention is applied, in other words, for are represented by the corresponding number shown beexarnple, 20 pots 1 plot used in Example B has such l w! a meaning that the preparation of this invention having 1-(2,4-dichlorophenoxyacetyl)-3,5-dimethyla certain concentration is applied to 20 pots, respecpyrazole I tively. This is applicable to the same term used in all 1-(4-chlorophenoxyacetyl)-3,5-dimethylpynazole II other examples. 1-(2,4,5-trichlorophenoxyacetyl) -3,5-dimethyl-4- Method: Respective aqueous solutions each containing chlorcfpyrazole "7"" In one of the following six compounds in various con- 1'(24'd1 ih1rophenoxyacetyl) centration are applied to the flowers with a brush, and Pyrazo e IV days rec ulred for ripening and the features of fruit-set Compounds Concentration Percentage of fmwset and fruit-development were observed. (p p m l) (2) Result.-In the following two tables, the compounds are represented by the corresponding numbers 20 100 shown below: 100

1-(2,4-dichlorophenoxyacetyl)-3,5-dimethylpyraz0le I H $8 8% 1-(4-chlorophenoxyacetyl)-3,5-dimethylpyraz-ole II 3 0 100 1- (2,4,5 -trichlorophenoxyacetyl) -3,5 -dirnethyl-4- In 8 33 chloropyrazole III 30 3g 95 1- (2-formyl-4-chlorophenoxyacetyl -3,5-dimethyl- 4O 32 pyrazole IV IV 5g 1-(2-forrnyl-4-chlorophenoxyacetyl)-3,5-dimethy1-4- 30 100 chloropyrazole V 40 100 1-(2-formyl-4-chlorophen-0xyacetyl)-3-methyl-5- 35 Contmuwflter) 66 Phenylpyrazole VI 1 p.p.m. means concentration in par-ts per million,

TABLE I Fruit-development (millimeter) Average weight Days re- Conc. Percentage of treated quired for Compounds (p.p.m. oi fruit-set Mean value of Mean value of fruit in the ri ening (percent) diameter of diameter of harvest time days) fruits 14 days fruit in the (grams) after the harvest time application Control (water).-. 0 48. 3 27x27 54x43 128.2 40.3 I 1 77. 2 31x31 53x43 137. 4 36. 5 1o 96. 1 39X36 67x51 145. e 32. 3 20 37. 7 35x35 65x51 140. 9 33. 1 40 35. 4 37x31 64x51 140. 2 33. 4 1r 1 53. 7 27 27 54x43 127. 7 39. 2 10 57. 6 30x23 54x45 129. 1 37. 1 20 59. 3 32x31 54x46 123. 9 37. 1 40 e0. 1 33x30 56X49 132. 5 35. 9 111 1 51. 6 28x27 54x46 123. 3 39. 2 10 57. 4 29x27 56x47 128.0 33. 7 2o 53. 7 30x23 56x47 129. 2 37. 1 40 63. 5 32x31 58x48 132. 6 35. 3

1 Cone. means concentration. 2 p.p.m. means parts per million.

TABLE 11 EXAMPLE D Fruit-develop- Growth inhibition test of young stage plants ment (average Days re- 60 Cone. Percentage weight of quired for Compounds (p.p.m. of fruit-set treated l'ruitin ripening (1) C0ndltl0ns.-

the harvest (day) time) (gram) Tested plants: Rice (Orvza sativa L.), cucumber (Cucwmis sativus L.) and Cocks foot (Panicum crusgalli Control L (water) o 47.2 126.0 40.3 J-

......... Test scale: 10 seeds per one plot, 3 repetitions.

40 145:2 1 Method: Germinating seeds of equal state of germination 100 80.3 139,0 are placed in a petridish (diameter: 9 cm.) on which 20 30.3 139.6 36.3 filter paper is spread and respectlve 5 cubic centimeters 38 2%: gag gig of the suspensions of each containing one of the followv1 ing compounds are poured. Then they are incubated 40 6013 1353 36:5 at 25 m dark- 100 57.2 136.4 37.8 (2) Result.F1ve days after treatment, root length and stem length are respectively measured to calculate inhibition percentages.

a Inhibition percentage= 1 EXAMPLE F Growth inhibition test and withering test by an applicacation to soil at pre-emergence (1) Conditions.-

Tested plants: Rice, soy bean, buck wheat and tomato.

Plant Rice Cucumber Cocks foot (Orr 2a sativa L.) (Oucumis sativus L.) (Panicum p.p.rn. crusgalli L.)

Inhibition Percentage (percent) Root Stem Root Stem Root Stem length length length length length length 1-(4-chloro-phenoxyacetyl)-3,5- 1 95 5 90 0 90 62 dimethylpyrazole. 95 0 100 93 91 100 93 0 100 38 93 93 1-(2,4-dichlorophenoxyacetyl)- 1 100 0 100 57. 9 84. 5 49. 6 3,5-dimethylpyrazo1e. 10 100 53. 6 97. 0 0 84. 7 61. 4 100 100 100 100 0 88. 3 66. 3

1 p.p.m. means parts per million.

EXAMPLE E Growth inhibition (2) Observati0n.Fourteen days after treatment, results are examined to calculate inhibition percentages and withering percentages.

Inhibition percentage= Fresh weight at treated plot Fresh Weight at non-treated plot W ithering percentage:

Number of completely withered plant Number of used test plant X 100 (3) Result.ln the following table, the compounds are represented by the corresponding numbers shown below.

1-(2,4-dichlorophenoxyacetyl) 3,5-dimethylpyrazole I 1-(2 formyl-4-chlorophenoxyacetyl)-3,5-di.methyl-4- chloropyraziole II Test scale: 1 pot ($4 are Wagners pot) per 1 plot,

about 10' plants per pot, 2 repetitions Method: Respective 10 cubic centimeters of the solutions of the following compounds per one plot is applied to soil at pre-emergence.

(2) Result-One month after treatment, the result is examined to calculate inhibition percentages and withering percentages. Inhibition percentages and withering percentages have the same meaning as those defined in Example E. a V

In the following table, the compounds are represented by the corresponding numbers shown below.

1-(4-chloro-2-methylphenoxyacetyl) 3,5-dimethylpyrazole I 1 (2,4,5 trichlorophenoxyacetyl)-3,5-dimethylpyrazole II 1-(4-chlorophenoxyacetyl) 3,5-dimethyl-4-chloropyrazole I11 1-(2,4-dichlorophenoxyacetyl) 3,5 dimethyl 4- chloropyrazole IV 1-(2,4,S-trichlorophenoxyacetyl)-3,5 dimethyl 4- chloropyrazole V :1-(2 chlorophenoxyacetyl) 3 chloromethyl-4- nitrosopyrazole i VI 1-(2,4dichlorophenoxyacetyl) 3,5 dimethyl 4- nitropyrazole VII l-(4-chlorophenoxyacetyl)-3,5-dimethylpyrazole VIII 1-(2,4 dichlorophenoxyacetyl) 3,5 dimethyldimethyl-4nitrosopyrazole III pyrazole IX 7 TABLE Plants Compounds Concentra- Rice Soy beans Tomato Buck wheat tion (percent) Inhibition Withering Inhibition Withering Inhibition Withering Inhibition Withering (percent) (percent) (percent) (percent) (percent) (percent) (percent) (percent) I 0. O3 0 0 20 0 43 10 34 0 0. 05 10 0 78 32 I00 100 100 II 0.03 3 0 34 0 68 20 45 12 0. 05 14 0 82 44 100 100 100 100 III 0. 03 5 0 22 0 44 10 30 0 0. O5 17 0 87 40 100 100 100 100 Concentrations in the present example are shown by weight-percentage.

TABLE-ontinued Plants Compounds Concentra- Rice Soy beans Tomato Buck wheat tion (percent) Inhibition Withering Inhibition Withering Inhibition Withering Inhibition Withering (percent) (percent) (percent) (percent) (percent) (percent) (percent) (percent) I 0.05 7.1 0 44. 0 23.1 0 39. 3 0 0.1 36. 4 0 73. 8 33. 4 57. 7 25.0 100 100 0. 5 36. 4 0 100 100 100 100 87. 5 75 II 0. 05 0 0 80. 9 66. 7 11. 6 0 25.0 25. 0

0.1 0 0 83. 9 66. 7 46. 2 0 0 0 0. 5 9.1 0 100 100 77.0 58.0 26. 8 25. 0 III 0. 05 27. 3 0 100 100 0 0 0 0 0.01 27. 3 0 74. 8 66. 7 11. 6 0 0 0 0. 5 0 0 100 100 53. 9 25. 0 10. 8 0 IV 0.05 18. 2 0 100 100 73. 1 50.0 39. 3 25. 0

0.1 0 0 100 100 100 100 12.5 0 0. 5 0 0 100 100 100 100 100 100 V 0.05 27. 3 0 100 100 88.8 75. 0 51. 8 25.0 0. 1 18. 2 0 100 100 100 100 87.5 75.0 0. 5 27.3 0 100 100 100 100 100 100 VI 0. 05 0 0 21. 6 0 0 0 0 0 0.1 0 0 18.2 0 13.4 0 16.4 0 0. 5 0 0 100 100 90. 0 60 20. 5 0 VII 0.05 0 0 10. 3 0 100 100 20. 5 0 0. 1 0 0 22. 8 0 100 100 26. 6 0 0. 5 50 0 100 100 100 100 100 100 VIII 0. 1 0 0 100 100 100 100 76. 0 60 0. 5 0 0 100 100 100 100 86. 8 60 1.0 40 0 100 100 100 100 100 100 2. 0 40 0 100 100 100 100 100 100 IX 0.1 0 0 35. 3 0 71. 2 50 64.0 38 0. 5 0 0 85. 0 50 96. 2 75 88. 2 50 1. 0 4O 0 100 100 100 100 100 100 2. 0 80 100 100 100 100 100 100 Concentrations in the present example are shown by weight-percentage.

EXAMPLE G EXAMPLE 3 Test for fruit-drop prevention (1) Conditions.

Test plant: Apple (Malus pumile Mill var dulcissima Koidz) Method: Solutions of various concentrations containing 1 (2,4 dichlorophenoxyacetyl)-3,5-dimethylpyrazole are applied to fruits and fruit-stalks about one month before the harvest time, and the difference in the number of dropped fruits between treated trees and nontreated ones is observed.

For the purpose of giving those skilled in the art a better understanding of the present invention, the following illustrative examples of presently-preferred embodiments of preparations of pyrazole derivatives and of the compositions containing pyrazole derivatives. In these examples, parts and percentages are by weight.

EXAMPLE 1 An emulsion comprising 0.1 part of 1-(4-chlorophenoxyacetyl)3,5-dimethylpyrazo1e, 0.3 part of polyoxyethylenesorbitane monolaurate, 50 parts of acetone and 49.6 parts of benzene, according to the invention, is useful in promoting fruit-set and fruit-ripening.

EXAMPLE 2 A solution comprising 02 part of 1-(2,4-dichloro-phenoxyacetyl)-3,5-dimethylpyrazole, 0.8 part of polyoxyethylenealkylarylether and 99 parts of acetone, according to the invention, is useful in promoting fruit-set and fruitdevelopment.

An emulsion comprising 0.5 part of l-(2,4-dichloro-phenoxyacetyl)-3,S-dimethyl-4-chloropyrazole, 1.5 parts of polyoxyethylenesorbitane monolau-rate and 98 parts of methylnaphthalene, according to the invention, is useful in promoting fruit-set and fruit-development.

EXAMPLE 4 A tablet comprising 0.1 part of 1-(2,4-dich1orophenoxyacetyl)-3,5-dimethylpyrazole in 97 parts of lactose, 10 parts of polyethylene glycol (5% methanol solution), 1.2 part of starch, and 1.2 part of talc, according to the invention, is useful in promoting fruit-set and fruit-development.

EXAMPLE 5 A tablet comprising 0.2 part of 1-(2,4,5-trichlorophenoxyacetyl)-3,5-dimethylpyrazole in 96.9 parts of lactose, 10 parts of polyethylene glycol (5 methanol solution), 1.2 part of starch and 1.2 part of talc, according to the invention, is useful in promoting fruit-ripening.

EXAMPLE 6 A powder comprising 2 parts of 1-(4-chlorophenoxyacetyl)-3,5-d-imethylpyrazole and 98 parts of talc, according to the invention, is useful in promoting root-initiation.

EXAMPLE 7 A wetting powder comprising 20 par-ts of 1-(2,4-dichlorophenoxyacetyl)-3,5-dimethylpyrazo1e, 4 parts of sodium ligninsulfonate, 4 parts of polyoxyethylenealkylarylether and 72 parts of clay, according to the invention, is useful in withering weeds.

EXAMPLE 8 An emulsion comprising 20* parts of 1-(2,4-dinitrophenoxyacetyl)-3,5-dimethyl-4-chfloropyrazole, 10 parts of methyln-aphthalene, according to the invent-ion, is useful in withering weeds.

EXAMPLE 9 A granule comprising 2 parts of 1-(2,4-dichlorophenoxyacetyl)-3,5-d-imethy1pyrazole and 98 parts of bentonite, according to the invention, is useful in withering weeds.

13 The following examples set forth presently-preferred exemplary embodiments of the preparation of compounds (I).

EXAMPLE 10 To a mixture of 20 parts of ethanol and parts of water are added 2 parts of 4-chlorophenoxyacethydrazide, 1 part of acetylacetone and 0.3 part of hydrochloric acid, and the mixture is refluxed for 2 hours. After cooling, the separated crystals are recrystallized from ethanol to give 1 (4 chlorophenoxyacetyl)-3,5-dimethylpyrazole as colorless scales melting at 1l2-113 C. Yield 2 parts.

Analysis.-Calculated: C, 58.98%; H, 4.95%; N, 10.58%. Found: C, 59.14%; H, 4.82%; N, 10.32%.

EXAMPLE 11 To 30 parts'of ethanol are added 2.3 parts of 2,4-dichlorophenoxyacethydrazide, 1 part of acetylacetone, and 0.3 part of 10% hydrochloric acid, and the mixture is refluxed for 1.5 hours. After cooling, the separated crystals are recrystallized from ethanol to give 1-(2,4-dichlorophenoxyacetyl)-3,5-dimethylpyrazole as colorless needles melting at 132-134 C. Yield 2.5 parts.

Analysis.-Calculated: C, 52.19%; H, 4.04%; N, 9.36%. Found: C, 52.40%; H, 4.25%; N, 9.29%.

EXAMPLE 12 To a mixture of 20 parts of ethanol and 10 parts of Water are added 2 parts of 2-chlorophenoxyacethydrazide, 1 par-t of acetylacetone and 0.3 part of 10% hydrochloric acid, and the mixture is allowed to react at 50 C. for 6 hours. After cooling, the separated crystals are recrystallized from ethanol to give 1-(Z-chlorophenoxyacetyl)- 3,5-dimethylpyrazole as colorless prisms melting at 124- 126" C. Yield 1.5 parts.

Analysis.-Calcu-lated: C, 58.98%; H, 4.95%; N, 10.58%. Found: C, 59.05%; H, 4.99%; N, 10.48%.

EXAMPLE 13 To a mixture of 30 parts of ethanol and 10 parts of water are added 2.3 parts of 2,4-dichlorophenoxyacethydrazide, 1.6 parts of benzoylacetone and 0.3 part of 10% hydrochloric acid, and the mixture is allowed to react at 6O"- C. for 10 hours. After cooling, the separated crystals are recrystallized from ethanol to give 1-(2,4-dichlorophenoxyacetyl)-3-methyl-5-phenylpyrazole as colorless needles melting at 118-119 C. Yield 1.6 parts.

Analysis.-Calculated: c, 59.86%; H, 3.90%; N, 7.75%. Found: C, 60.01%; H, 3.77%; N, 7.26%.

EXAMPLE 14 To a mixture of 50 parts of ethanol, 20 parts of fwater, and 10 parts of 10% hydrochloric acid are added 4.6 parts of 2,4-dichlorophenoxyacethydrazide and 3.4 parts of ethyl ethoxymethylenecyanoacetate, and the mixture is stirred at room temperature (20 to 30 C.) for 5 hours. The separated crystals are recrystallized from ethanol to give 1-(2,4 dichlorophenoxyacetyl)-4-ethoxycarbonyl-5- aminopyrazole as colorless crystals melting at 162 C. Yield 2 parts.

Ahalysis.Calc-ulated: C, 46.95%; H, 3.65%; N, 12.01%. Found: C, 46.23%; H, 3.67%; N, 11.63%.

EXAMPLE '15 To a mixture of '30 partsofethanol, 5 parts of Water and 0.2 part of 10% hydrochloric acid are added 2.1 parts of 4-c-hloro-2-methylphenoxyacethydrazide and 1 part of acetylacetone. The mixtureis heated at 60 C. for 3 hours. After cooling, theseparated crystals are recrystallized from ethanol to give 1 (2 methyl 4- chlorophenoxyacetyl) 3,5' dimethylpyrazole as colorless prisms melting at 137.5138.5 C. Yield2 parts.

Analysis.Calcula ted; C, 60.32%; H, 5.42%; N, 10.05%. Found: C, 60.33%; H, 5.53%; N, 10.32%.

EXAMPLE 17 To a mixture of 40 parts of ethanol, 10 parts of water and 1 part of 10% hydrochloric acid are added 2.6 parts of 2,4 dinitrophenoxyacethydrazide and 1 part of acetylacetone, and the mixture is 'heated at 60 C. for 1 hour. After cooling, the separated crystals are recrystallized from ethanol to give 1 (2,4 dinitrophenoxyacetyl)-3,5-dimethylpyrazole as pale-yellowish prisms melting at 161-162" C. Yield 2 parts.

Analysis.-Caloulated: C, 48.75%; H, 3.78%; N, 17.50%. Found: C, 48.91%; H, 3.94%; N, 17.57%.

EXAMPLE 18 To a mixture of 35 parts of ethanol, 5 parts of Water and 0.3 part of 10% hydrochloric acid are added 2 parts of 4-chlorophenoxyacethydrazide and 1.3 parts of 3-chloro-n-pentane-2,4-dione, and the mixture is heated at 60 C. for 1.5 hours. After cooling, the separated crystals are recrystallized from ethanol to give 1-(4- chlorophenoxyacetyl) 3,5 dimethyl 4 chloropyrazole as colorless plates melting at 151l53 C. Yield 1.3

arts. a p Analysis.Calculated: C, 52.19%; H, 4.04%; N, 9.36%. Found: C, 51.69%; H, 3.85%; N, 8.84%.

EXAMPLE 19 To a mixture of 40 parts of ethanol, 10 parts of water and 0.5 part of 10% hydrochloric acid are added 2.3 parts of 2,4-dichlorophenoxyacethydrazide and 1.3 parts of 3-ehloro-n-pentane-2,4-dione, and the mixture is refluxed for 1 hour. After cooling, the separated crystals are recrystallized from ethanol to give 1-(2,4-dichlorophenoxyacetyl) 3,5 dimethyl 4 chloropyrazole as colorless needles melting at 127128 C. Yield 2 parts.

Analysis.Calculate-d: C, 46.76%; H, 3.32%; N, 8.39%. Found: C, 46.88%; H, 3.37%; N, 8.16%.

EXAMPLE 20 To a mixture of 35 parts of ethanol, 15 parts of .Water and 0.7 part of 10% hydrochloric acid are added 2.7 parts of 2,4,5 trichlorophenoxyacethydrazide and 1.3 parts of 3-chloro-n-pentane-2,4-dione. The mixture is heated at 60 C. for 2 hours. After cooling, the separated crystals are recrystallized from ethanol to give 1-(2,4,5- trichlorophenoxyacetyl) 3,5 dimethyl 4 chloropyrazole as colorless scales melting at 136.5-138" C. Yield 2 parts.

Analysis.-Calculated: C, 42.42%; H, 2.74%; N, 7.61%. Found: C, 42.28 H, 2.84%; N, 7.64%.

EXAMPLE 21 To a mixture of 40 parts of ethanol, 10 parts of water and 0.5 part of 10% hydrochloric acid are added 2 parts of 2-chlorophenoxyacethydrazide and 1.5 parts of 3- nitro-n-pentane-2,4-dione, and the mixture is refluxed for 1 hour. After cooling, the separated crystals are recrystallized from ethanol to give 1 (2 chlorophenoxyacetyl) 3,5 dimethyl 4 nitropyrazole as colorless prisms melting at 192493? C. Yield 1.3 parts.

Analysis.-Calculated: C, 50.41%; H, 3.90%; N, 13.57%. Found: C, 50.40% H, 4.22%; N, 13.55%.

EXAMPLE 22 To a mixture of 40 parts of ethanol, parts of Water 1nd 0.5 part of 10% hydrochloric acid are added 2 parts of 4-chlorophenoxyacethydrazide and 1.5 parts of 3- 5 nitro-n-pentane-2,4dione, and the mixture is refluxed for 1 hour. After cooling, the separated crystals are recrystallized from ethanol to give 1-(4-chlorophenoxyacetyl)- 3,5-dimethyl-4-nitropyrazole as colorless needles melting at 184186 C. Yield 1.4 parts.

Analysis.Calculated: C, 50.41%; H, 3.90%; N, 13.59%. Found: C, 50.65%; H, 4.03%; N, 14.03%.

EXAMPLE 23 To a mixture of 35 parts of ethanol, 5 parts of Water and 0.5 part of 10% hydrochloric acid are added 2.3 parts of 2,4-dichlorophenoxyacethydrazide and 1.5 parts of 3-nitro-n-pentane-2,4-dione, and the mixture is refluxed for 2 hours. After cooling, the separated crystals are recrystallized from ethanol to give 1-(2,4-dichlorophenoxyacetyl)-3,5 dimetl1yl 4 nitropyrazole as colorless prisms melting at 161l62 C. Yield 1.7 parts.

Analysis.Calculated: C, 45.37%; H, 3.22%; N, 12.21%. Found: C, 45.54%; H, 3.32%; N, 12.26%.

EXAMPLE 24 To a solution of 1.5 parts of 3,5-dimethylpyrazole in 5 parts of pyridine, is dropwise added 2,4-dichlorophenoxyacetylchloride. After the mixture is stirred for 1 hour, 40 parts of water are added. The separated crystals are recrystallized from acetone-Water to give 1-(2,4-dichlorophenoxyacetyl) 3,5 dimethylpyrazole as colorless needles melting at 132134 C. Yield 2.4 parts.

Analysis.-Calculated: C, 52.19%; H, 4.04%; N, 9.3%. Found: C, 52.06%; H, 4.01%; N, 9.63%.

To a solution of 1.6 parts of 3,5-dimethyl-4-chl-oropyrazole in 5 parts of pyridine, is added dropWise a solution of 3 parts of 2,4,5-trichlorophenoxyacetylchloride in 5 parts of acetone. After one hours stirring, 100 parts of water are added to the reaction mixture. The separated crystals are recrystallized from acetone to give 1-(2,4,5- trichlorophenoxyacetyl)-3,5-dimethyl-4-chloropy1'azole as colorless scales melting at 136.5138 C. Yield 3.2 parts.

Analysis.-Calculated: C, 42.42%; H, 2.74%; N, 7.61%. Found: C, 42.28%; H, 2.84%; N, 7.64%.

EXAMPLE 27 To parts of ethanol containing 1 part of 10% hydrochloric acid are added 2.3 parts of 2-hydroxymethyl-4- chlorophenoxyacethydrazide and 1 part of acetylacetone. The reaction mixture is heated at 50 C. for 1 hour. After cooling, the separated solid is recrystallized from dimethylformamide-ethanol to give 1-(2-hydroxymethyl-4-chlorophenoxyacetyl)-3,5-dimethylpyrazole as colorless needles melting at 133 C. Yield 2.4 parts.

Analysis.Calculated: C, 57.06%; H, 5.14%; N, 9.51%. Found: C, 56.89%; H, 4.96%; N, 9.43%.

The following compounds can be synthesized in similar manner.

TABLE [Remarks for solvent for recrystallization"; DMF dimethyliormamido] R R R A X., Melting Point Solvent for reerystal- Appearance 0! C.) lization crystals Br CH CH9 2-Cl 157-158 Colorless needles. 8%2- H Cz 5 CH2 2Cl 98-100 Colorless prisms. CHa- C1 CzH50- -CH2- 2-01 141-142 Do. CH Br CzHsO-- OH3 2-C1 133-134 D0. CH3 H CaHs- OH3 2-C1 138-138. 5 D0. OH Cl CeH5- -CHz- Z-Cl 185-186 D0. CH Br CsH5- CHz Z-Cl 190-191 D0. CH3- H CHs CHa- 3-Cl 100-101 D0. CHa- N02 CH3 -CHz 51-01 164-166 D0. CH3 C1 CHa- -CH: 3-Cl 108-109 D0. CHa- BI CHz- -CH2 3-Cl -121 D0. CH H C H 0 CH1 3-01 101 Colorless crystals. CHs Cl C2H50-- CH2- 3-01 77 Colorless prisms. CH Br C2H5O- -CH3 3-C1 D0, CH H CaH5 CH2 3-C1 D0. CH3- C1 C5H5- CHg- 3-Cl Do. (311 Br CgH5-- CHz- 3-Cl D0. 0113- H C2H50- -CH2 4-01 Colorless needles. CHa- Cl CzH5O- CH 4-C1 D CH3- B! C2H50- -CHz 4-Cl D 011 H OBH5 CHz- 4-01 Colorless prisms: CH C1 CsHs- CHz 4-Cl D0, CH Bl CaHs- -OHz 4-Cl D0, CH3- NO: CH CHz Z-OHal-Cl Do, CH Cl CH3 -CHz Z-CHa-A-Ol D CH Br (3113- CH; 2-CHa-4-Cl Do. CH H CzH O-- CH2- 2-CH3-4-Cl Do, CH Cl CzH O- -CHz 2-CHz-4-Ol D0, CH Bl CzH50 -CH2- Z-CHa--Cl D 'CH3 H CaH5- CH2- 2-CH3-4-C1 D0. CH Cl CoH5 -CH 2-CH3-4-C1 D0, CH Br CBH5 CHz- Z-CHaA-Cl D0. CH Br orn- CH2- 2,4-d -Cl Do. CH3- H 0250- C 2 .4-(11-01 107-108 -do Colorless crystals. CHa- I 2 5 z- Colorless prisms. CH B1 CzHsO- -CH2 ZA-dl-Cl D0, CH3- Cl CeHs- OH2 2,4-d -Cl Colorless needles. CH3- 1' Co zs H2 4411-01 Do. OH;- H CH3- -CH(CHa) 2,4-di-Cl Colorless prisms. CH3- N0z CHa- CH(CHa)- 2,4- i-C1 97-99 n-Hexane Colorless crystals.

TABLEGontinued [Remarks for solvent for recrystallization ;DMF=dimetl1ylfo1-mamido] R R R A Xn Melting Point Solvent for recrystal- Appearance of 1 lllation crystals CH3- Cl CHa -GH(CH3) 2,4.di-Cl -101 Colorless needles. C a- Br CH3- -CH(CHa)- 2,4-di-Ol Colorless prisms, CHa- H CzHaO- -CH(CHa)- 2,4-di-Cl 73-74 Colorless needles, CHs- C1 C2H5 O CH(CH3)- 2,4-di-Cl Colorless prisms, CH3 Br 01115 0-,- CH (CH3) 2,4-di-Cl 80-82 D0. 0113- H CaHs- -CH(CH3) 2,4-di-Cl 109-110 Colorless needles, CH3- Cl CuHs CH(OH3)- 2,4-di-Cl 129-130 Do. CHs Br GBHb- CH(CH 2,4-di-Cl 132-132. 5 Do. CHr- H CH3- Hr 2,5-di-Cl 112-113 Colorless prisms, CHa- NO CHz- -CH2 2,5-di-Cl 160-161 Do. CHa- Cl CH3- -CH; 2,5-di-Cl 150-151 D0. CHa- Br CH3-- -CH2-- 2,5-di-Cl 157-158 D0. CHs- H C H5O- -CH3 2,5-di-Cl 121-122 Do. CH:4- Cl CgHsO- -CHz- 2,5-di-Cl 115-116 D0. CHa Br 0 115 O-- CH- 2.5-(li-Cl 91-92 D CI-Is- H CtHr- CH 2,5-(ii-Ol -121 Do. 0113- C1 CaH5 CHg- 2,5di-Cl 116-117 D CHa- Br CAH5- OH; 2.5-!11-01 113-115 Do. CHa H CH: CH2- 6-(11- D0. CHs --N03 CHa- -CH 2,6-di-Cl 177-179 Do. CHa' C1 CHa- CHr- 2,6-dl-Cl 148-149 D0. CHr- Br CH3- CHz- 2,6-di-Cl 145-146 Do. 0113- H CzH O- OH; 2,6-di-Cl 81-83 Do, CH3- Cl CzHisO- CHz- 2,6-(11-01 122-124 D0, CHa- Br O H5O- -OH 2,6-di-Cl 147-148 Colorless needles, CHa- H CuHr- CHz 2,6-di-Cl 133-134 Colorless crystal CHa- Cl C H5- CH7- 2.6-di-Cl 160-161 Colorless needles, CHa- Br CsHr- --CH 2,6-(ii-Cl 162-163 Do. CHa- NO; CH3- CH7 2,4,5-tri-Cl 1 Do. CHa Br CHa- CHz- 2,4,5-tri-Cl 154-154. 5 D CHa- H 02H50- -CH- 2,4,5-tri-Ol 123-124 Colorless crystals. CHac1 CZHBO- CH2 2,4, 5-tri-Cl 107-108 Do, CHa Br C H O CH1- 2,4,5-trl-Cl 120 Colorless prisms, 011:.- H C H CH2 2,4,5-tri-Cl 131-133 Colorless needles. CHzr- C1 CqH5- CH; 2, 4. 5-tri-Cl 159. 5-160. 5 Colorless prisms, CHa- Br Ou/Hr- -CHz- 2,4.5-tri-Cl 157-15 D CHa- H CH3 CHz 2-N0 130-131 D CH3 NO CH3- CH1- 2-NO 184-185 Colorless needles. CHs- Cl CH3- -CHz- 2-NOz- 139-140 Colorless prisms, CH3- B! CH3- -CH1 2-NO3 153-154 0 0113- H O0H6- -CHa 2-N0 147-148 Colorless needles. CH3' Cl CoH5 -CH2 2-Nog 169-170 D CHa Br CuH5 CH; 2-NO5 176-177 D CHs H 0,1150- CHT 2-NO2- 109-111 Colorless crystals. CHa CHs- CHz- 3-NOg- 137-137. 5 Colorless rism CH3' -NO1 CH3- CH7-- 3-N0g- 148-149 Do, CH3 Cl CH3- CHg- 3-N0z -156 D CHa Br 0113- -OH: 3-NOz- 167-168 Colorless crystals, CHa- H C2H5O- -CHz- 3-N02- 109-11 Colorless prisms. CH3 H CeH5- -CHz- 3-N'Og 139-140 D0, CH3- Cl CuH|5 CHn-- 3-N0r- 131-132 D0, CHa- Br 0!;11 CH; 3-NO 115-117 Colorless crystals. CHa- H CH3- -CH5 4-NO2 168- Colorless scales. CH3- NO3 CH -CH;- 4-N0g Colorless crystals. CHa- Cl CH3- CHg- 4-N0, 176-178 Colorless prisms. CH3 BI CH3- CH5 4-NO1 -191 D() CHa H CaH5- CH2 4-NO1 220-222 Colorless plates. CH3 Cl CoH5- CH t-NO, 164-166 Colorless needles. CHs Br 0511 -CH 4-NO2 1 9-151 Do. CH3 H CH -CHz- 2,3,4,6-tetra-Cl 159-160 Colorless crystals. CH3- Cl CH3- CH 2,3,4,6Ftetra-Cl 178-179 Colorless prisms. a- H 05115- -CHz 2,3,4,6-tetra-Cl 146-147 CHa- H CH -CH1 2,3,4,5,6-penta-Ol 180-181 Colorless crystals. CH3 C1 (3113- CH2 2.3.4.5,6-penta-Cl D H (CHni CHz- 4-01 120 D0. H -CH=CHCH=CH- 'CHz- 4-Cl Do. H CH=CHCH=CH CH 2.4-(11-01 Colorless needles. H -CH=CHCH=CH- -CH2 2.4,5-tri-Cl Colorless crystals. H --CH=CHCH=CH- CH(CHa)- 2,4-di-Cl Colorless needles.

Although the present invention has been described in of hydrogen, halogen, nltro, nitroso, cyano, lower alkoxyconjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims.

Having thus disclosed the invention, what is claimed 1s:

1. The method of regulating growth of plants which comprises applying thereto, in effective amount, a pyrazole derivative of the formula R U-RJ wherein R stands for a member selected from the group consisting of halogen, lower alkyl, aralkyl and aryl, R stands for a member selected from the group consisting carbonyl, butylene conjugated with carbon atom in 5- position, and but-1,3-dienylene conjugated with carbon atom in 5-position, R stands for a member selected from the group consisting of hydrogen, hydroxyl, amino, lower alkyl, aralkyl, aryl, lower alkoxy, butylene conjugated with carbon atom in 4-position, and but-1,3-dienylene conjugated with carbon atom in 4-position, X stands for a member selected from the group consisting of halogen,

hydrogen, nitro, lower alkyl, acyl, hydroxyalkyl, alkoxyalkyl and lower alkoxy, A stands for lower alkylene, and n stands for an integer of 1 to 5.

2. The method of regulating growth of plants which comprises applying thereto, in effective amounts, a pyrazole derivative of the formula ozanacs 19 wherein each of R and R is a member selected from the group consisting of CH and C H A is selected from the group consisting of CH and X is a member selected from the group consisting of H, Cl, methyl, HOCI-I and CHO, and n stands for an integer of 1 to 5.

3. The method according to claim 1 wherein R is methyl, R is H, R is methyl, A is --CH X is Cl, and n is 2, the Cl atoms being in the 2- and 4-positions on the phenyl nucleus.

20 References Cited UNITED STATES PATENTS 3,020,276 2/ 1962 Hughes et al 712.5 X 3,200,128 8/1965 Wagner 71-2.5 X

FOREIGN PATENTS 523,256 3/ 1956 Canada.

OTHER REFERENCES Thompson et a1.: Botanical Gazette, 107, pp, 475-507.

LEWIS GOTTS, Primary Examiner.

JAMES O. THOMAS, IR., Assistant Examiner. 

1. THE METHOD OF REGULATING GROWTH OF PLANTS WHICH COMPRISES APPLYING THERETO, IN EFFECTIVE AMOUNT, A PYRAZOLE DERIVATIVE OF THE FORMULA 